The present invention relates to a device discharging or exhausting heated air generated by an electromotor or motors (hereinafter simply referred to as a motor), powered with a battery or batteries, for use in a forklift truck.
More particularly it relates to a device speedily discharging heated air, generated or produced by a motor placed in an almost completely covered space, by utilizing a cooling fan which is provided with in the motor and avails itself as a ventilator of the covered or closed space.
A battery-powered forklift truck is generally provided with a pair of motors, one is for propelling the main body of the forklift truck (hereinafter simply referred to as a body) and the other is for driving the hydraulic pump, both of which motors are strictly limited with respect to the space available for the location thereof. The motors are (hereinafter a singular form instead of plural form will be used for the convenience sake) often required to be placed in a relatively closed and poorly-ventilated place; it is not necessarily possible to place the motor in a well-ventilated open space. When the motor is placed on the upper portion of the body, as is sometimes observed, it is usually obliged to be hooded or covered for the sake of good appearance. Moreover the motor is sometimes subject to be placed together with heat-sensitive parts, which preferably should be placed in a cool place.
An electric motor is generally a heat-generating apparatus, to a certain extent, so it is often provided with a cooling fan to keep it cool or an exhaust fan to discharge heated air therefrom. When the motor is disposed in a closed space, consequently, the heated air emitted from the motor will be accumulated in the space not only to affect heat-sensitive regulating apparatus or the like placed in the same space but also to overheat the motor itself. This is the reason why openings for ventilation have been conventionally provided to otherwise closed space within which a motor for a forklift is positioned.
It can hardly be expected that a forklift truck is naturally ventilated by wind or moving air, as the traveling speed thereof is normally low and a forklift truck is frequently subject to indoor operation; only natural draught or convectional ventilation can be expected at the best. While a motor for the hydraulic pump is working this tendency is particularly noticeable, because the forklift truck is in a stationary state in such a situation. In conventional battery-powered forklifts undesirable effects from heat from the motor and/or overheating of the motor itself actually frequently occur.